An elastic squeeze bottle, when collapsed by squeezing, should resiliently return after squeezing, to its normal shape.
In this respect, it is different from other collapsible containers made of malleable material and which remain collapsed after squeezing as in the case of the conventional tube containing toothpaste.
Squeeze bottles are used to package viscous products, such as hair shampoo, diswashing soaps and food products, such as ketchup. Such a package conventionally has the bottle mouth provided with a dispensing spout closed by a screw cap or the like to prevent leakage of the product when the package is shipped or layed on its side by the user.
For greater convenience, a squeeze bottle can be provided with an automatic value which is elastically biased to normally closed position and which is opened by the pressure of the product displaced when the bottle is squeezed and more or less collapsed for dispensing the bottled product. Thereafter, to permit air to be sucked back into the bottle so it can resiliently return to its uncollapsed or normal shape, the valve must be provided with a check valve which permits inward passage of the air but prevents outward passage of the product.
An example of an automatic valve capable of handling such products is disclosed by the Laauwe U.S. Pat. No. 4,057,177, Nov. 8, 1977. In this case the valve embodies a check valve in the form of a so-called duck bill. A substantially improved form is disclosed by the Laauwe pending application Ser. No. 969,796, filed Dec. 15, 1978 on which U.S. Pat. No. 226,342 issued Oct. 7, 1980.
Both of the above valves are unique in that they are operative when the squeeze bottle contains a viscous product. The type of valve involved has conventionally been designed with an elastic diaphragm having a central discharge or dispensing orifice and which, acting like a Belleville spring, is pressed by its inherent resiliency against an inner valve head, the diaphragm surrounding its orifice forming a valve seat. With viscous material between the mating surfaces of the valve head and valve seat, it was previously necessary to make the diaphragm so strongly elastic to squeeze the product from the valve surfaces for closing, that the squeezing pressure on the bottle was too great to be acceptable to the public. The Laauwe valves have overcome this problem, the valve of the pending application being particularly easy to open while positively reclosing.
However, both of the Laauwe valves incorporate a check valve for venting the bottle so that after squeezing the bottle can spring back to shape, both valves using the so-called duck bill. Both Laauwe valves use only two injection-molded plastic parts, which are snapped together, making them capable of mass production at low cost as required for their provision in numbers of millions as required to supply the market with the packages. However, if the need for the check valve could be eliminated, the parts and manufacturing costs could be reduced.
If a viscous product dispensing package using a squeeze bottle with an automatic valve could be mass produced at adequately low cost, it would not only be of great benefit in general, but would open up opportunities for the introduction of new packaging concepts.
For example, there has never been a practical replacement for the old familiar solid cake of soap which has for so long been preferred by the public because of its relatively low cost and because for use it had only to be picked up and used with water. However, this advantage is also a disadvantage because with the cake of soap lying on the kitchen sink, bathroom basin or tub receptacle, etc., a large amount of the soap melts and becomes a loss. Its substitution by a squeeze bottle having an automatic valve and containing viscous liquid soap, with the bottle possibly shaped to simulate the familiar cake of soap, would offer attractive possibilities from the commercial viewpoint as well as that of the purchasing public, if the package could be made to sell at a competitive price, keeping in mind that the saving in soap and the greater convenience could offset the price differential.
The main object of the present invention has been to provide a viscous product dispensing package comprising the squeeze bottle containing the viscous product, the automatically opening and reclosing valve of the type described, and completely eliminating the need for the venting action valve previously required.